A review on reproductive biology and breeding of Indian shad, Tenualosa ilisha

The Indian shad (Tenualosa ilisha), popularly known as hilsa is a commercial fish species of the Indo-Pacific region. It is an anadromous fish that migrates from sea to freshwater river for spawning. Due to unavailability of hatchery seed production and farming technology of hilsa, the demand is completely dependent on the wild resources. Therefore to conserve the natural stock and realize its aquaculture potential, ample of research nave been carried out to understand the biology of wild stock of hilsa. However, significant knowledge gap exist in the area of reproductive endocrinology, spawning behaviour and nutritional requirement during migration. Therefore, in the current review, we conducted systematic review to address the knowledge gaps, challenges in captive seed production programme of hilsa. Published research data showed hilsa is an oviparous, iteroparous and polygamous fish, which spawn five to six times in their lifespan during well-defined two peak breeding seasons in Indo-Pacific region viz. monsoon and winter. Researchers have also standardized the artificial (on-board) breeding from wild caught brooders through dry stripping. However, captive breeding from domesticated broodstock of this species is yet not established due to scarcity of knowledge on reproductive physiology. Current research in this line showed that the rearing of wild seed of hilsa for two years either in freshwater or brackishwater pond showed sexual maturity of hilsa (stage IV), which instigate the further environmental, hormonal and dietary manipulation will pave the way to develop the hatchery technology of hilsa. In this background, the current review is prepared to discuss the recent advancement in reproductive biology and possible way out for captive breeding of hilsa.